Cartridge for liquid or pasty dentifrice

ABSTRACT

A cartridge for liquid or pasty dentifrice is described which is adapted for use in a fountain toothbrush having a bristle carrier, a guiding sleeve member connected to the latter for receiving the cartridge therein and serving as a handle of the toothbrush, duct means leading from the bottom part of the sleeve member through the bristle carrier to a set of bristles on the latter, an actuating means with which the cartridge is adapted to be brought into engagement, which actuating means comprise a piston borne by the bristle carrier at its end away from the bristles, which cartridge is hermetically closed at the end thereof destined for facing away from the bristle carrier, and has a reservoir for dentrifice in its interior and an outlet passage of the latter reservoir opening in that frontal face of the cartridge which is destined to face the bristle carrier; the outlet passage is adapted for receiving therein the said piston in displaceable, sealing engagement; furthermore, the cartridge comprises a sealing membrane hermetically closing off the said outlet passage prior to introduction of the cartridge into the sleeve member, and the membrane is removable by piercing means associated with the piston, at the time of the aforesaid introduction of the piston into the said outlet means.

United States Patent Del Bon Oct. 7, 1975 CARTRIDGE FOR LIQUID 0R PASTYDENTIFRICE [5 7] ABSTRACT 75 Inventor; Franco De] Bo, zofingem Acartridge for liquid or pasty dentifrice is described Switzerland whichis adapted for use in a fountain toothbrush having a bristle carrier, aguiding sleeve member con- [73] Asslgnee: Tnsa Burstenfabnk AG nected tothe latter for receiving the cartridge therein 22] Ffl d; M 21 1974 andserving as a handle of the toothbrush, duct means leading from thebottom part of the sleeve member [21] Appl. No: 453,403 through thebristle carrier to a set of bristles on the latter, an actuating meanswith which the cartridge is [30] Foreign Application Priority Dataadapted to be brought into engagement, which actuat- June 6, 1974Switzerland 003401/74 P z pistohn 1F; by l? B .Z rier at its en away romt e rlst es, w 1c cartrl ge 1974 Germany 2400514 is hermetically closedat the end thereof destined for 52 US. Cl 401/134; 401/286 W away F thebristle Came and has a [51] Int. cl. A46B 11/00 for demrfice in itsintefior and an outlet Passage [58] Field of Search 401 /132-135, of thelatter reservc openng that frontal face 401/190, 286 288 the cartridgewhich is destined to face the bristle carrier; the outlet passage isadapted for receiving therein [56] References Cited Ehe hsaid pistorli1in dispgaceable, sealing enlgagement;

urt ermore, t e cartri ge comprises a sea ing mem- UNITED STATES PATENTSbrane hermetically closing off the said outlet passage Young prior tointroduction of the cartridge into the leeve $5 5 8 3 member, and themembrane is removable by piercing means associated with the piston, atthe time of the aforesaid introduction of the piston into the saidoutlet means.

6 Claims, 4 Drawing Figures [1111/11/11]. IIIIIIIIIII-IIIIIIIII US.Patent Oct. 7,1975

7 I I I A III CARTRIDGE FOR LIQUID OR PASTY DENTIFRICE BACKGROUND OF THEINVENTION This invention relates to a cartridge for liquid or pastydentifrice, which cartridge is adapted for use in a fountain toothbrushhaving a bristle carrier and, connected to the latter, a preferablyrigid-walled guiding sleeve member serving as a handle and destined forreceiving the cartridge therein, the said bristle carrier having a ductleading from the bottom part of the sleeve member through the bristlecarrier to the bristles on the latter, as well as actuating means whichthe cartridge is adapted to engage, which actuating means comprise apiston borne by the bristle carrier at its end remote from the bristles.

A fountain toothbrush of this kind has been described in U.S. Pat.application No. 453,391 (Case 261/267) filed on the same day as theinstant application. Such fountain toothbrushes may be equipped with arefillable dentifrice reservoir in which case the wall of the reservoirwill constitute itself the handleof its toothbrush. As has beenmentioned, the wall of the handle should preferably be rigid, at leastto a sufficient degree so as not to yield to manual pressure by thefingers of the holder.

Due to the fact that most of the time a fountain toothbrush will becarried by the user clipped in a pocket with the rear end of thetoothbrush pointing downwardly, sealing means are required which must beparticularly safe and are accordingly complicated and costly.

The problems of mounting such actuating means with perfect seal in therear end wall of the reservoir, away from the bristles, are completelyavoided in the fountain toothbrush described in the above-mentionedpatent application No. 453,391 while, at the same time, the expense forseparate actuating means is eliminated.

Preferably, the fountain toothbrush of the intially described type isprovided with arresting means preventing a complete withdrawal of thepiston out of engagement with the reservoir during normal use of thetoothbrush.

It has been found that, surprisingly, a relative short stroke of thepiston into the reservoir is sufficient to convey a small portion of adentifrice of satisfactory liquidity onto the bristles, even when only aminor portion of the internal volume of the reservoir remains filledwith the dentifrice. When, however, dispensing toothpastes ofconventional consistency, it is necessary to plunge the piston more orless deeply into the interior of the reservoir, depending on the amountof dentifrice present in the latter.

Fountain toothbrushes which have a movable piston in the dentifricereservoir have been described, for instance in U.S. Pat. Nos. 2,214,144,2,305,158 and 3,039,476 as well as in French Pat. No. 769,734. However,in all these devices, the piston must be actuated from the rear end ofthe reservoir by means of an actuating means passing through the endwall of the reservoir.

The problems of sealing such actuating means in the reservoir wall arecompletely avoided in the fountain toothbrush of the initially describedtype while, at the same time, the expense for separate actuating meansis eliminated.

Apart from the discharge opening destined for receiving the piston fordisplacement therein, the rigid reservoir wall has no further opening.

OBJECT AND SUMMARY OF THE INVENTION It is an object of the presentinvention to provide a reservoir for use with the type of fountaintoothbrush initially described.

This object is attained by an exchangeable cartridge according to theinvention, to be filled or being filled with dentifrice, which cartridgehas a single discharge opening being sealed, prior to insertion into thelastmentioned fountain toothbrush, by means of a sealing membrane whichcan be removed or perforated during the insertion of the cartridge intothe guiding sleeve member and before or during introduction of thepiston into the discharge opening of the cartridge. Preferably, thecartridge will protrude with its closed rear end portion from the openrear end of the sleeve member serving as a handle for the toothbrush.

As has been mentioned before, when a dentifrice of suficiently lowviscosity is used, a short inward displacement of the piston into thecartridge will be sufficient to convey an adequate amount of dentifriceto the bristles, even when the degree of filling in the cartridge islow. I

At least part of the duct leading through the bristle carrier shouldpreferably be formed as a capillary tube, thus preventing the liquiddentifrice to pass through to the bristles while the piston is in itsmost withdrawn end position relative to the front end of the reservoirfacing toward the bristle carrier.

When using a liquid dentifrice of conventional viscosity, the capillarytube preferably has a diameter of about 0.5 to 1.5 mm, whereas theremaining portion of the duct can have a diameter above 1.5 mm andpreferably one of about 2 mm. Very satisfactory results were obtainedwith a duct 2 mm in diameter, over most if its length whereof only theopening towards the set of bristles showed a capillary width of 0.8 mmand Weleda mouth-water or Chlorodont mouth-water of a commerciallyavailable composition were used.

Cap means for sealing can be provided especially for use under extremeconditions, e.g. when the toothbrush is taken along in aeroplanes,flying through the stratosphere, or when using dentifrice liable to bedecomposed by air. Such cap means close the mouth of the duct from thepiston into the reservoir while the piston is in neutral postion.Elastic sealing means are preferred for this purpose which may be formedas a projection of the inner wall of the handle surrounding thereservoir, whereby said means preferably lock the duct leading out ofthe side of a projection of the piston into the reservoir, while thepiston is in the abovementioned maximally withdrawn end position.Abutment means determining the inward displacement of the pistonrelative to the reservoir in the handle are preferably formed by aprojection on the piston or on the bristle carrier carrying the same,which projection protrudes through a cut-out in the adjacent wall of thehandle. These abutment means can be manipulated by a finger, i.e. theindex finger, of the same hand that holds the handle. In this case, aninward displacement of the piston from the above-described end-positionof only 2 mm into the reservoir is sufficient, when using liquiddentifrice of conventional viscosity.

In order to be well adapted for use in the initially described fountaintoothbrush, the cartridge according to the invention is hermeticallyclosed at its rear end, i.e. at its end away from the bristle carrierwhile in its frontal end wall destined to face the bristle carrier, thecartridge has an outlet opening of the dentifrice reservoir located inits interior, into which outlet opening the piston mentionedhereinbefore must be sealingly inserted, a sealing membrane which closesa discharge opening during storage prior to use being adapted forperforation by a thorn member or the like perforating means associatedwith the piston.

When inserting the piston in the discharge orifice, the thorn memberfirst perforates the sealing membrane of the cartridge and as the pistonis advanced further in the discharge orifice in the direction toward theinterior of the cartridge, dentifrice is conveyed from the cartridge byway of passage means associated with the piston and further through theduct through the bristle carrier to the bristles.

Preferably, the wall of the cartridge bears abutment means for aresetting member associated with the bristle carrier and serving toreturn the cartridge, after actuation, as described above, to itsinitial postion wherein no flow of dentifrice to the bristles occurs.These abutment means may comprise, for instance, a recess in theabove-mentioned frontal end wall of the cartridge and adapted forreceiving therein one end of a resetting spring.

Preferably, abutment means for limiting a displacement of the cartridgeinside the sleeve member are provided on the outside wall of thecartridge, which abutment means engage corresponding abutment means onthe bristle carrier.

In order to facilitate manufacture of the cartridge from thermoplasticresin material by injection molding processes requiring only simpletools, it is preferred to produce the cartridge with an open rear endand then to close the rear opening by means of a lid member which can bewelded, e.g. by ultrasound, thereon to provide a hermetic seal, afterthe cartridge is filled.

The cartridge may be of approximately rectangular or circular orhorseshoe-shaped cross-sectional area, the latter being preferablyadapted to fit snugly, but well displaceably, into the internalcross-sectional area of the sleeve member on the bristle carrier. Incase the guiding sleeve member is of correspondingly somewhat larger,horseshoe-shaped cross-section and in case the narrow flat side of thehorseshoe defines a face of the wall of the sleeve memberlocated. on theside of the bristle carrier opposite that bearing the bristles, then theguiding sleeve member 'will constitute a handle which is particularlycomfortable and safe to grasp by the hand of the user when brushing histeeth with the initially described fountain toothbrush.

The invention will be better understood, and further objects andadvantages will become apparent from the ensuing detailed specificationof preferred but merely exemplary embodiments taken in conjunction withthe drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows in axial sectional view afirst embodiment of the cartridge according to the invention insertedinto a fountain toothbrush adapted for receiving the cartridge andhaving a guiding sleeve member therefore, which sleeve member isfastened on the bristle carrier of the toothbrush and serves as thehandle of the same;

FIG. 2 is a cross-sectional view of the same embodiment of the cartridgeas well as of the sleeve member surrounding the same seen in a planeindicated by II-II in FIG. 1;

FIG. 3 shows an embodiment of the cartridge according to the inventionsimilar to that shown in FIGS. 1 and 2, but in perspective view; and

FIG. 4 shows an embodiment of the combination of the cartridge andtoothbrush with a cap thereon.

DETAILED DESCRIPTION OF THE EMBODIMENTS The fountain toothbrush shown inFIGS. 1 and 2 comprises as main parts a bristle carrier 33 which bearsat its forward end a set of bristles 4 while about its rearward end face33a, remote from the bristle bearing front end, there is provided anelongation in the form of a rigid walled sleeve member 31 which is openat its rearward end and which serves as the handle of the toothbrush. Acartridge 30 containing liquid or pasty dentifrice has been insertedthrough this open sleeve end. From the rearward end face 33a of thebristle carrier 33 a duct 12 extends toward the bristle-bearing end ofbristle carrier 33 and opens through a lateral outlet duct 19 betweenthe bristles 4. The cross-sectional area of this outlet duct 19 is sodimensioned that an adequate capillary action is exercised on thedentifrice as a function of the viscosity of the latter. Thereby,dentifrice is prevented from flowing out of the discharge orifice ofduct 19 when the toothbrush is not actuated, even while the toothbrushis held with its bristles downward and is shaken or waved to and fro.

Duct 12 opens via enlarged end portion 38 in the end face 33a of bristlecarrier 33, and a piston 37 is force fit into the enlarged duct portion38. Piston 37 has an axial passage 32 therethrough. Thedentifrice-filled cartridge 30 which is inserted in the sleeve member 31has in its front face 30b which faces toward the bottom of the interiorof sleeve member 31, a discharge passage which is in free communicationwith the interior 30d of cartridge 30, which passage 34 is so located inthe inwardly directed front face 30b of cartridge 30 and which is ofcourse of such diameter that piston 37 will enter passage 34 and will beengaged sealingly displaceably in passage 34 during introduction ofcartridge 30 into sleeve member 31. Prior to this insertion into sleevemember 31; the filled cartridge 30 is hermetically sealed by means of athin membrane 30e. On the outside wall of cartridge 30 there is provideda nose 300 of somewhat resilient material which can be brought into snapengagement with a groove or window 31a in the wall of sleeve member 31.Abutment of nose 300 against the end wall of groove or window 310situated in axial forward direction, i.e. toward the bristles 4 limitsthe inward movement of cartridge 30, in the same direction.

Recesses 33b and 35, provided respectively in the rearward end face 33aof bristle carrier 33, in the interior of sleeve member 31, on the onehand and in the opposite frontal face 30b of cartridge 30, facing towardthe bristles 4, on the other hand, are aligned with one another andreceive each one end of a compression spring 36 which serves asresetting spring. The displacement of cartridge 30, caused by thisspring 36, in outward direction relative to the rearward open end ofsleeve member 31, is limited by nose c of cartridge 30 abutting againstthe rearward end wall of groove or window 31a. This will also preventcartridge 30 from becoming separated unintentionally from sleeve mem ber31. However, if a stronger pull is exerted on the rear end of cartridge30, which protrudes from the open rearward end of rearward sleeve 31,the somewhat resilient nose 30c will be disengaged from groove or window31a, and an empty cartridge can thus be removed from sleeve member 31 tobe replaced by a new, full cartridge. Instead of having nose 300 made ofresilient material, it is also possible to make the wall of cartridge30, in particular in-the vicinity of nose 300, of somewhat resilientmaterial. When a window 31a is provided as shown in FIG. 1, it ispossible to urge nose 30c inwardly, c.g. with the nail of a finger, andsimulta neously move the nose 30c slightly outwardly relative to sleevemember 31, thereby disengaging nose 33 from window 31a whereby cartridge30 can be easily drawn out of sleeve member 31. For the same purpose,window 30a may also be arranged nearer the forward end, e.g. in themiddle zone of sleeve member 31. A thorn 39, protruding from the frontalface of piston 37 facing toward reservoir 30d, which thorn surroundspassage 32 through the piston, will perforate the membrane 30e ofcartridge 30, when the latter is pushed sufficiently far into sleevemember 31. Preferably, this will occur shortly before, or simultaneouslywith nose 30c entering into snap engagement with the groove or window3111.

In the positions of cartridge 30, sleeve member 3], piston 37 and spring36 as shown in FIG. 1, the fountain toothbrush is in non-actuatedcondition. When using the same, a protective cap (not shown) is removedfrom the toothbrush, and the latter is held in the hollow of one handwith the end thereof bearing bristles 4 protruding out of the plam ofthe hand past the little finger. The thumb of the same hand thus comesto rest on the rearward end of the cartridge at 3011. By brieflypressing the thumb downward, cartridge 30 is moved into sleeve member 31until nose 30c abuts against the forward end wall of groove or window31a. Thereby, a small amount of dentifrice is caused to flow out ofreservoir 30d and is conveyed via piston passage 32, duct 12 of thebristle carrier, and the capillary outlet duct 19 to the bristles 4 andspreads on the latter.

This dispensing of dentifrice takes place partically independently ofthe degree of filling of reservoir 3011. When nose 30c abuts against theforward end wall of groove or window 31a. the thumb can release at oncethe rear end of cartridge 30, and resetting spring 36 will pushcartridge 30 back into its starting position.

The embodiment of a cartridge 40 shown in perspective view in FIG. 3, isof horseshoe-shaped cross section. Reservoir 40:1 in the interior ofcartridge 40 has a discharge outlet via a passage 44 in the cartridgefrontal face 40b to be inserted facing toward the bristles 4. Moreover,a recess 45 is provided in frontal face 40b, which recess serves forreceiving therein one end of the resetting spring (shown in FIG. 1)v

The dash-dotted line I-I indicates the plane in which this cartridge haspractically the same sectional view as shown in FIG. 1. However, thenose 400 is provided on the opposite side of the cartridge as comparedwith nose 30c shown in FIG. 1. correspondingly, the groove or window insleeve member 31, into which nose 400 is to enter into snap engagement,must be located on the opposite side of sleeve member 31 nearer to theconnection of the latter to the bristle carrier 33.

The mass production of the cartridges shown in FIGS. 1 to 3, fromthermoplastic resin materials by modern injection molding techniques iscarried out most conveniently by making the cartridge with its rear endopen, but having the sealing membrane 306, 40e produced integral withthe remainder of the cartridge wall, and closing the cartridge, afterfilling in the dentifrice, by means of a lid 30a, 40a being madepreferably of the same material as the remainder of the cartridge andsealing the lid hermetically, preferably by ultrasonic welding, onto theremaining wall of the cartridge, without affecting the quality of thedentifrice in the cartridge.

What is claimed is:

l. A cartridge for liquid or pasty dentifrice, combined with a fountaintoothbrush having a bristle carrier, a guiding sleeve member connectedto the latter for receiving the cartridge therein and serving as ahandle of the toothbrush, a duct means leading from the bottom part ofthe sleeve member through the bristle carrier to a set of bristles onthe latter, an actuating means with which the cartridge is adapted to bebrought into engagement, said actuating means comprising a piston borneby the bristle carrier at its end away from the bristles, whichcartridge is hermetically closed at the end thereof destined for facingaway from said bristle carrier, and has a reservoir for dentifrice inits interior and an outlet passage of said reservoir opening in thefrontal face of said cartridge being destined to face said bristlecarrier, said outlet passage being adapted for receiving therein saidpiston in displaceable, sealing engagement, said cartridge comprising asealing membrane hermetically closing off said outlet passage prior tointroduction of said cartridge into said sleeve member, said membranebeing ruptured by piercing means associated with said piston, at thetime of the aforesaid introduction, and abutment means pro vided in thewall of said cartridge comprising a recess in the frontal face of saidcartridge and adapted for receiving therein a resetting spring.

2. The combination as described in claim 1, wherein said cartridgefurther comprises on the outer wall thereof, stop means adapted forlimiting displacement of the cartridge relative to said guiding sleevemember in a direction toward and away from said bristle carrier, saidstop means being engageable by corresponding stop means on said bristlecarrier or on said sleeve member. 7

3. The combination as described in claim 1, having a wall being open atthe end destined for facing away from said bristle carrier, and a lidmember hermetically closing said open wall end.

4. The combination as described in claim 1, being of approximatelyrectangular cross section.

5. The combination as described in claim 1, being of horseshoe-shapedcross section.

6. A cartridge usable in the combination as described in claim 1,comprising a reservoir for dentifrice in its interior and an outletpassage of said reservoir opening in a frontal face of said cartridge, asealing membrane hermetically closing off said outlet passage prior touse of said cartridge in said combination, and abutment means providedin the wall of said cartridge comprising a recess in the frontal face ofsaid cartridge and adapted for receiving therein a resetting spring.

1. A cartridge for liquid or pasty dentifrice, combined with a fountaintoothbrush having a bristle carrier, a guiding sleeve member connectedto the latter for receiving the cartridge therein and serving as ahandle of the toothbrush, a duct means leading from the bottom part ofthe sleeve member through the bristle carrier to a set of bristles onthe latter, an actuating means with which the cartridge is adapted to bebrought into engagement, said actuating means comprising a piston borneby the bristle carrier at its end away from the bristles, whichcartridge is hermetically closed at the end thereof destined for facingaway from said bristle carrier, and has a reservoir for dentifrice inits interior and an outlet passage of said reservoir opening in thefrontal face of said cartridge being destined to face said bristlecarrier, said outlet passage being adapted for receiving therein saidpiston in displaceable, sealing engagement, said cartridge comprising asealing membrane hermetically closing off said outlet passage prior tointroduction of said cartridge into said sleeve member, said membranebeing ruptured by piercing means associated with said piston, at thetime of the aforesaid introduction, and abutment means provided in thewall of said cartridge comprising a recess in the frontal face of saidcartridge and adapted for receiving therein a resetting spring.
 2. Thecombination as described in claim 1, wherein said cartridge furthercomprises on the outer wall thereof, stop means adapted for limitingdisplacement of the cartridge relative to said guiding sleeve member ina direction toward and away from said bristle carrier, said stop meansbeing engageable by corresponding stop means on said bristle carrier oron said sleeve member.
 3. The combination as described in claim 1,having a wall being open at the end destined for facing away from saidbristle carrier, and a lid member hermetically closing said open wallend.
 4. The combination as described in claim 1, being of approximatelyrectangular cross section.
 5. The combination as described in claim 1,being of horseshoe-shaped cross section.
 6. A cartridge usable in thecombination as described in claim 1, comprising a reservoir fordentifrice in its interior and an outlet passage of said reservoiropening in a frontal face of said cartridge, a sealing membranehermetically closing off said outlet passage prior to use of saidcartridge in said combination, and abutment means provided in the wallof said cartridge comprising a recess in the frontal face of saidcartridge and adapted for receiving therein a resetting spring.